Author: van der Geer, S.B.
Paper Title Page
MOPPC079 Modelling of the EMMA ns-FFAG Ring Using GPT 319
  • R.T.P. D'Arcy, S. Jolly
    UCL, London, United Kingdom
  • J.K. Jones, B.D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • S.B. van der Geer
    Pulsar Physics, Eindhoven, The Netherlands
  EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed-Field Alternating Gradient (ns-FFAG) accelerator whose construction at Daresbury Laboratory, UK, was completed in the autumn of 2010. The energy recovery linac ALICE will serve as an injector for EMMA, within an energy range of 10 to 20 MeV. The injection line consists of a symmetric 30 degree dogleg to extract the beam from ALICE, a matching section and a tomography section for transverse emittance measurements. This is followed by a transport section to the injection point of the EMMA ring. The ring is composed of 42 cells, each containing one focusing and one defocusing quadrupole. Acceleration over many turns of the EMMA machine has recently been confirmed. In some cases the bunch will traverse upwards of 100 turns, at which point the effects of space-charge may be significant. It is therefore necessary to model the electron beam transport in the ring using a code capable of both calculating the effect of and compensating for space-charge. Therefore the General Particle Tracer (GPT) code has been used. A range of injection beam parameters have been modeled for comparison with experimental results.